Internal-combustion engine



E. SCHMID INTERNAL COMBUSTION ENGINE Apx'il 29 1924.-

Filed July 23. 1923 Patented Apr. 29, 192d.

FFKE.

ERNST SCHMID, OF ANNECY, FRANCE.

INTERNAL-COMBUSTION ENGINE.

Application filed Ju1y 23,

To all whom it may concern:

Be it known that I, ERNsT SOHMID, a citizen of the Republic of Switzerland, residing at Annecy, France, have invented certain new and useful Improvements in Internal- Combustion Engines, of which the following is a specification, reference being had therein to the accompanying drawing.

The present invention relates to improvements in, internal combustion engines in particular to valve gear of the so-called valveless combustion engines.

With certain valveless internal combustion engines the distribution is effected by means of longitudinally moving. piston valves. In case of four stroke cycle engines it is desirable that the piston valve be moved very quickly in the moment of the exhaust and of the suction and that it remains almost stationary during the compression and the combustion. In order to obtain such a distribution it has already been proposed to derive the motion of the piston valve from two crank pins rotating with different speeds the actions of which are cumulative during the exhaust and the suction and tend to compensate each other during the compression and the combustion.

According to the present invention the gear for effecting the distribution comprises a hollow cylinder which is linked to a crank pin and a piston linked to a second crank pin and adapted to slide in said hollow cylinder, said parts, the cylinder and the piston, sliding relatively to each other, and the connections to the crank pins being in alignment.

This gear shows the advantage that the generation of eccentric turning moments so which would affect the gear parts unfavourably' is avoided.

A constructional form of the valve gear according to the present invention fitted to an engine is shown by way of example on the accompanying drawings, in which:

Fig. 1 is a vertical section through an internal combustion engine provided with the valve gear, and

Fig. 2 is a section along line IIII of 60 Fig. 1 through the gear.

1 denotes the main crank shaft of the internal combustion engine, the piston 2 of which reciprocates in the cylinder 8. The inlet and exhaust ports 4 and 5 respectively of the cylinder are controlled by a piston valve 6. The gear for operating the piston 1933. Serial No. 653,257.

valve consists of the following parts: Crank shafts 7 and 8 are provided with crank pins 9 and 10 respectively, which rotate with different speeds. The rotation being derived from a gear wheel 11 fixed to the main crank shaft 1, through the intermediate gear wheels 12,18 and 14 and the gear wheels 15 and 16 fixed to the crank shafts 7 and 8 respectively. The diameter of the gear wheel 16 is smaller than that of the gear wheel 15 so that the speed of the crank pin 10 is greater than that of the crank pin 9.

To the crank pin 10 a hollow cylinder 17 is linked by means of a connecting rod head 18' and to the crank pin 9 a rod 19 is linked by means of head 20, the rod 19 being adapt,

ed to slide as a piston in the cylinder 17. The cylinder 17 is provided with two lateral pins 21, 22 to which the piston valve 6 is linked by the intermediary of a piston rod 23, to the end of which a cap 24, provided with two pins 25, 26 is fixed, and links 27, 28.

Owing to the difierent speed of the crank pins 9 and 10 the known effect results that the actions of the crank pins are cumulative during the exhaust and the suction causing a very quick movement of the piston valve, whereas these actions tend to compensate each other during the compression and the combustion so that the piston valve remains almost stationary in this case.

With this arrangement the cylinder 17 and the piston 19 are guided along a considerable part of their lengths so that in conjunction with the feature that these parts have the longitudinal axis common to them and a vertical plane passing through these axes passes also through the centres of the lengths of the crank pins 9 and 10 and through the axis of the piston rod 23 of the piston valve 6 any jamming and eccentric turning movement is excluded, whereby friction and wear and tear of the gear parts are reduced to a minimum.

I claim:

1. A valve gear for so-called valveless internal combustion engines comprising in combination two cranks rotating at difierent speeds, means interposed between said cranks and the main crank shaft of the internal combustion engine for rotating said cranks, a hollow cylinder linked to one of said cranks, a piston adapted to reciprocats in said hollow cylinder and linked to the other crank, a member for controlling the distribution in said internal combustion engine, and an operative connection between said cylinder and the controlling member, the cylinder and the piston having a longitudinal axis common to both, so that any jamming of these parts is avoided.

2. A valve gear for so-called valveless internal combustion engines, comprising in combination two cranks rotating at different speeds, means interposed between said cranks and the main crank shaft of the internal combustion engine for rotating said cranks, a hollow cylinder linked to one of said cranks, a piston adapted to reciprocate in said hollow cylinder and linked to the other crank, a member for controlling the distribution in said internal combustion engine, and an operative connection between said cylinder and the controlling member, the parts of the connection being so arranged that the cylinder and the piston have a longitudinal axis common to both and that a vertical plane passing through this axis is a plane of symmetry of all the connecting parts interposed between said cylinder and the controlling member to avoid any jamming of the parts.

3. A valve gear for so-called valveless internal combustion engines, comprising in combination two cranks rotating at different speeds, means interposed between said cranks and the main crank shaft of the internal combustion engine for rotating said cranks, a hollow cylinder linked to one of said cranks, a piston adapted to reciprocate in said hollow cylinder and linked to the other crank, a member for controlling the distribution in said internal combustion engine, lateral pins provided on said cylinder and between said cranks, links co-operating with said pins, an operative connection between said links and the controlling member, the parts of the connection being so arranged that the cylinder and the piston have a longitudinal axis common to both and that a vertical plane passing through this axis is a plane of symmetry of all the connecting parts interposed between said cylinder and the controlling member to avoid any jamming of the parts.

In testimony whereof I afiix my signature.

ERNST SCHMID. 

